Optical cable and process for producing the same

ABSTRACT

Supporting elements designed as independent profiles are provided between ribbon stacks of optical waveguide ribbons of an optical cable. The supporting elements contribute to positing securing of the ribbon stacks within the opposite table.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to optical cables and, more particularly,this invention relates to an optical cable with a plurality of ribbonstacks of optical waveguide ribbons which are arranged in at least onelayer around a core element.

2. Description of the Related Art

An optical cable of this type is described in German Patent No. DE-A1-3839 109. Its cable core consists of a plurality of chamber elements withapproximately rectangular openings which are arranged around atensile-load-resistant element. The chamber elements serve to receiveribbon stacks of optical waveguide ribbons.

Although an optical cable constructed in this manner from chamberelements provides, with appropriate wall thickness, reliable protectionfor the ribbon stacks against radial and circumferential forces, for thepositional securing of the chamber elements, however, a special shapingof the chamber elements with sector-shaped side walls is necessary.

One aspect of the present invention is directed to a method in which,the positional securing of the ribbon stacks in optical cable can beensured in a simpler manner.

This object is achieved in an optical cable of the type mentioned abovehaving supporting elements designed as independent profiles which areprovided in the interspaces formed by the ribbon stacks, such that thesupporting elements contribute to a positional securing of the ribbonstacks.

In the optical cable of the present invention, it is therefore notnecessary to provide specially shaped chamber elements. By virtue ofthis design, both the construction and the production of an opticalcable with a plurality of ribbon stacks are simplified. According toanother aspect of the invention, it is even possible to eliminate thechamber elements entirely. A design of this type is distinguished inthat despite the fact that the ribbon stacks are free of chamberelements, they can be adequately secured in their position by arrangingsupporting elements in their interspaces.

According to another aspect of the invention, the profiles of thesupporting elements extend radially somewhat further outwardly than theribbon stacks. Thus, with this design, the supporting elements can exerta supporting pillar function with respect to radially acting transversecompressive forces.

According to another aspect of the invention, the supporting elementsalmost completely fill the interspaces between the ribbon stacks, thatis to say without tolerance space. Thus, it is advantageously ensuredthat the optical waveguide ribbons collected to form ribbon stacks areheld in their places in the respective ribbon stacks around thecircumference. This allows positional securing of the ribbon stacks inthe circumferential direction. This design is particularly useful whentransverse compressive forces act in the circumferential direction. Inthis case it is desirable to use a flexible material for the supportingelements.

According to yet another aspect of the invention, the supportingelements only partly fill the interspaces between the ribbon stacks,that is to say there is an empty space between two adjacent ribbonstacks. They then serve primarily as radially extending spacers andsupporting pillars in the interspaces of the ribbon stacks. For thisfunction of the supporting elements, a stiff, smooth material which canbe internally supported is desirable. In order to prevent this kind ofsupporting element from displacing or turning over, it is desirable thatthe supporting elements be fixed in their position.

The invention also relates to a process for producing an optical cable,wherein the supporting elements are designed as independent profileswhich are introduced into the interspaces formed by the ribbon stacks insuch a manner that the ribbon stacks are secured in their position.

The invention and its preferred embodiments are explained in greaterdetail below with reference to the in which:

FIG. 1 illustrates a cross section through an enlarged view of anoptical cable which incorporates the present invention.

FIG. 2 illustrates a cross section of a modification of the opticalcable shown in FIG. 1 having a tubular core element.

FIG. 3 illustrates a cross section of an optical cable of the inventionhaving two layers of ribbon stacks and supporting elements locatedbetween them.

FIG. 4 illustrates a diagrammatic view of a device for carrying out theprocess according to the present invention.

FIG. 5 illustrates a modified of the device shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows, in enlarged form, a cross section through the constructionof an optical cable OC1. Its design has as cable elements a core elementKE, a layer, applied thereto, of preferably approximately rectangularribbon stacks BS1 to BSn with, also preferably, approximately flat,rectangular, preferably optical waveguide ribbons BD1 to BDk in eachcase, supporting elements SE1 to SEn inserted between these ribbonstacks BS1 to BSn in each case, a cover layer SS and an outer jacketwith a reinforcement BW and an outer sleeve AH. For improved clarity,only a few ribbon stacks BS1-BSn and, included between them, supportingelements SE1-SEn are drawn in FIG. 1. For this reason, their dimensionsare shown enlarged.

In the center of the circular-cylindrical core element KE, atensile-load-resistant and compression-resistant, circular-cylindricalelement CE is provided for protecting the optical cable OC1 againsttensile and compressive loads. This tensile-resistant element CE mayadvantageously be constructed, for example, of a plurality of steel oraramid fibers. Onto this tensile-load-and compression-resistant elementCE, a thickening layer AS is applied. The latter is dimensioned suchthat a desired number of ribbon stacks BS1 to BSn may be arrangedannularly in a layer directly around the thickening layer AS. Thethickening layer AS is desirably made of a relatively hard material, forexample, such as, PE or PP. In this manner the core element KE can actas a stiff, compression-resistant foundation for the layer, which isdirectly applied to it, of ribbon stacks BS1 to BSn and the supportingelements SE1 to SEn incorporated there-between in each case.

The ribbon stacks BS1 to BSn of optical waveguide ribbons are arrangedbearing directly against the core element KE by, for example, laying upon the latter annularly in a layer. k optical waveguide ribbons BD1 toBDk in each case are combined with m optical waveguides LW1 to LWm ineach case to form one of the n ribbon stacks BS1 to BSn. The ribbonstacks BS1 to BSn have an approximately rectangular profile in crosssection. In FIG. 1, the ribbon stack BSn, for example, comprises fiveoptical waveguide ribbon lines with in each case eight opticalwaveguides. In the cross sectional diagram of FIG. 1, the innermostribbon line BD1 of this stack BSn preferably bears directly, nestling inthe circumferential direction, against the thickening layer AS of thecore element KE. In this sectional plane, the innermost ribbon line BD1thus runs curved in an arcuate manner. On this innermost ribbon lineBD1, the other four ribbon lines are stacked in layers radially outward,these ribbon lines nestling essentially loosely against one another.Between the ribbon lines BD1-BDk and/or in the remaining interspaces ofthe cable core, conventional bundle materials or filling materials canexpediently be introduced to obtain longitudinal watertightness. To holdthe ribbon lines BD1 to BDk in each case at their positions in theribbon stacks BS1 to BSn, they may, if appropriate, be adhesively bondedto one another and/or to the core element KE by means of an adhesivefilling material. (Remaining interspaces may also be advantageouslyprovided with this adhesive filling material.) PIB-containing materials,for example Naptel materials (Naphta-Chemic.), are advantageous for thispurpose. As an additional measure against the lateral slipping of theribbon lines BD1 to BDk of the ribbon stacks BS1 to BSn, the latter areexpediently dimensioned such that their radial extent is smaller thantheir extent in the circumferential direction, that is to say they arewider than they are high. Since, by virtue of this dimensioning, thecontact surface of the ribbon stacks BS1 to BSn on the core element KEis enlarged, and at the same time their surface-area of action in theradial direction with respect to transverse compressive forces isreduced, a cable construction with such ribbon stacks BS1 to BSn is to acertain extent more insensitive to transverse compressive forces. Theseribbon stacks BS1 to BSn advantageously extend between 1 mm and 3 mm,and preferably between 1.5 mm and 2 mm, in the radial direction. Theirextent along the circumference is desirably chosen so as to be between1.5 mm and 5 mm, is preferably between 2 mm and 3 mm.

By the fact that the ribbon stacks BS1 to BSn are applied bearingclosely, preferably wound helically, directly against the longitudinalaxis of the circular-cylindrical core element KE, a more compact,rotationally symmetrical cable construction with constant externaldiameter results. The winding space available in the circumferentialdirection on the core element KE can thus be utilized optimally, so thata high packing density of ribbon stacks BS1 to BSn with ribbon lines BD1to BDk can be obtained in the circumferential direction withsimultaneous minimization of the cable diameter.

It is possible, if appropriate, for better space utilization to providethe optical waveguide ribbons BD1-BDk within a stack with an increasingnumber of optical waveguides towards the outside, so that the ribbonstack obtains an approximately wedge-shaped cross section. In thismanner, an improved space utilization is obtained in the region of thecable core.

For the protection of the ribbon stacks BS1-BS11, the latter may also belocated within in chamber elements. In FIG. 1, a chamber element CA2 ofthis type is drawn as a thick line and thus encloses the ribbon stackBS2. These chamber elements, CA2 for example, preferably have anapproximately U-shaped cross section and are preferably open towards theoutside. The present invention is subject to many variations,modifications and changes in detail. It is intended that all matterdescribed throughout the specification be considered illustrative only.Accordingly, it is intended that the invention be limited only by thespirit and scope of the appended claims. These chamber elements need nosector-shaped side walls because their positional securing is effectedby the supporting elements SE1-SEn. The chamber walls may also be verythin, that is to nay filigreed, in design, it not being necessary forthem to have either a supporting effect in the radial direction or aposition-stabilizing effect in the circumferential direction. Opticalwaveguides may be inserted into these chamber elements either loosely,if appropriate, or preferably combined as an approximately rectangularbundle.

A lay length of between 400 and 700 mm is expediently chosen for theribbon stacks BD1-BDn.

In FIG. 1, the supporting elements SE1-SEn are applied from the outsidein the interspace (interstice) between two adjacent chamberless ribbonstacks in each case (for example with the aid of a lay up operation).Two types of supporting elements SE1-SEn can be inserted into theinterspaces of the ribbon stacks BS1-BSn. In the first case, thesupporting elements SE1-SEn fill the interspaces virtually completely.In this case a flexible material is desirably chosen for them. In thesecond case the supporting elements SE1-SEn only partly fill theinterspaces. A stiff, in particular internally supported, material isadvantageously chosen for these.

In the first case, the supporting elements desirably have anapproximately triangular or wedge-shaped profile in cross section (cf.FIG. 1) to fill the interspaces between the ribbon stacks BS1-BSn ascompletely as possible.

In order to secure the chamberless ribbon stacks BS1 to BSn with theribbon lines BD1 to BDk with respect to their position around thecircumference, that is to say to hold their ribbon lines BD1 to BDk inthe circumferential direction in the respective stack and in place, thesupporting elements SE1 to SEn extend in the radial direction at leastexactly as far as the ribbon stacks BS1 to BSn. The supporting elementsSE1 to SEn lie with their inner end directly on the core element KE. Bythis means it is ensured that the supporting elements SE1 to SEn fulfilltheir function as independent, position-securing separating walls orintermediate walls, supported on the core element KE, for the ribbonstacks BS1 to BSn. In the region of the contact surface of therespective supporting elements SE1 to SEn on the core element KE (base),their outer walls desirably contact the outer walls of the respectivetwo adjacent ribbon stacks BS1 to BSn. The respective two adjacentribbon stacks BS1 to BSn have a clearance (gap width) of between 0.5 mmand 1.5 mm there. In FIG. 1, for example, the supporting element SEncompletely fills the narrow inner gap SP of the interstice tip at thebase of the two adjacent ribbon stacks BSn and BS1. The gap SP betweenthe two innermost ribbon lines BD1 bearing directly against the coreelement KE, at the base of the two adjacent ribbon stacks BS1 and BSn,is thus completely bridged by the supporting element SEn. Since theinterstices between the ribbon stacks BS1 to BSn enlarge in a V-shapedmanner radially outwardly, the wall thickness of the supporting elementsSE1 to SEn is desirably also enlarged outwardly. They fill the emptyspace between two adjacent ribbon stacks BS1 to BSn as far as possiblecompletely to laterally support their side walls of ribbon lines BD1 toBDk loosely laminated one on top of the other. The incorporatedsupporting elements SE1 to SEn thus act as laterally supporting buffersbetween the ribbon stacks BS1 to BSn. In the event of kinking, bending,torsion or compressive loads, this prevents to a certain extent theribbon lines from being displaced in each case from their stack assemblyor even detached. In the circumferential direction, the supportingelements SE1 to SEn expediently have a wall thickness of at least 0.25mm, and is preferably between 0.5 and 1.5 mm, in the interior region.For the supporting elements SE1-SEn, at least 2 mm, in particularbetween 3 mm and 5 mm, are chosen in the circumferential direction inthe exterior region.

To assist the buffer and holding function of the supporting elements SE1to SEn in the circumferential direction, a relatively easily deformablematerial is desirably chosen for them. This preferably has a modulus ofelasticity of between 0.001 and 1 N/mm². Materials preferably suitablefor this purpose are, for example, profiles of flexible PU foam, thick,soft wool or cotton fibers, yarns or rovings of textile filaments orglass filaments, foam rubber materials, etc.

These materials may desirably be additionally provided with conventionalswelling agents to ensure close bearing of the supporting elements SE1to SEn, in the interstices, against the side walls of the ribbon linesBD1 to BDk loosely laminated to form ribbon stacks BS1-BSn.

If appropriately designed, the relatively soft supporting elements SE1to SEn may additionally also provide a certain protection against radialforces. For this purpose, the radial extent of the supporting elementsSE1 to SEn is advantageously chosen so as to be larger than the radialextent of the ribbon stacks BS1 to BSn. In particular, the profiles ofthe supporting elements SE1 to SEn may project beyond the stacks BS1 toBSn by 0.5 mm to 2.5 mm. With the aid of these measures, it is alsoachieved, with a low stiffness of the supporting elements SE1-SEn, thatthe latter absorb radially acting forces in the manner of absorbentpillars. This mechanism is obtained in particular in the interactionwith the core element KE acting as a compression-resistant foundation.If, for example, a transverse compressive force acts radially inwards inthe region of the supporting element SE1 on the optical cable OC1, thesupporting element SE1 is somewhat compressed and elastically deformed.By virtue of the direct bearing of the supporting element SE1 againstthe core element KE, however, this force is absorbed and directedradially inwardly to the core element KE. By this means, a compressionof the ribbon stacks BS1 to BSn is to a certain extent avoided.

In the second case, the supporting elements SE1-SEn only partly fill theinterspaces (interstices) between the ribbon stacks BS1-BSn. They arethus placed into the interspaces with, in each case, an empty space onboth sides, that is to say towards their two adjacent ribbon stacks. Thesupporting elements SE1-SEn then serve primarily as radially extendingspacers and supporting pillars with respect to forces acting radially. Astiff, smooth material is desirably chosen for this kind of supportingelements SE1-SEn. To assist the pillar and supporting effect of thesupporting elements SE1 to SEn, a material with an elasticity modulus ofat least 500-5000 N/mm, preferably between 700 and 2000 N/mm², canexpediently be used. They advantageously project above the ribbon stacksBS1-BSn by approximately 0.5-1 mm. By means of this measure and becauseof their stiffness, a defined clearance between the ribbon stacksBS1-BSn and a closed cover layer SS additionally applied to thesupporting elements is thereby ensured. A free compression space SR assafety zone in the event of radial forces occurring is thus available.

The remaining gaps between the respective two adjacent ribbon stacksadvantageously permit a certain displaceability of the individualelements with respect to one another without stressing of themoccurring. In this arrangement, the supporting elements SE1-SEnsecondarily fulfill the function of separating walls and represent akind of spacer also in the circumferential direction. To prevent thiskind of supporting elements SE1-SEn from displacing or turning over, forexample directly after lay up, they are desirably fixed in theirposition. The fixing may be carried out, for example, at the base of thecore element KE and/or at the radially outer end of the supportingelements SE1-SEn. For example, the supporting elements SE1-SEn may, forexample, be adhesively bonded onto the core element KE and/or placed orplugged into suitable, prepared depressions of the core element KE. InFIG. 1, a groove-shaped depression VT in the core element KE forreceiving the supporting element foot of the supporting element SEn isindicated with dotted lines. At their radially outer end, the supportingelements SE1-SEn may be surrounded for example by an external, closedcover layer SS for positional fixing. The fixing may preferably also becarried out with a reinforcement helix which is applied helically to thesupporting elements SE1-SEn. It is also possible to adhesively bond thesupporting elements SE1-SEn to the cover layer or the reinforcementhelix. If appropriate, a certain degree of fixing is also possible byfilling the remaining interspaces with an adhesive, viscous material(PIB-containing material). The danger of turning over is also reduced bythe fact that the supporting elements SE1-SEn run helically around thecable longitudinal axis and thus form a type of supporting ring.

The supporting elements SE1-SEn may, seen in cross section, also becomposed of varying materials. They may be in particular internallysupported. For example, in the case of the supporting element SEn ofFIG. 1 a supporting body STn, indicated with dot-dash lines, extendsradially over the entire length of this supporting element. Thissupporting body STn is composed of a relatively hard,low-compressibility material for a defined, radial spacing, inparticular for a compression-resistant pillar function in a radialdirection, whereas those regions of the supporting element SEn remainingat the right and left have cushioning properties and serve only for thepositional securing of the adjacent ribbon stacks BS1 and BSn in thecircumferential direction.

For positional securing, a stiff supporting body QTn runningtransversely to the radial extent of the supporting element SEn may alsobe advantageously incorporated, in particular injected. In FIG. 1, thissupporting body QTn is drawn with dot-dash lines in the supportingelement SEn. The supporting body QTn is expediently located in theradially outer region of the supporting element SEn. By this means, itadvantageously has a preferred bending plane, which makes turning overof the supporting element SEn more difficult. This type of supportingelement preferably acts in the circumferential direction. A combinationof the two supporting bodies STn and QTn finally leads to aT-girder-like, optimized supporting body TTn, which combines theadvantages that: it provides the supporting element SEn with acompression-resistant pillar function in the radial direction and at thesame time with a sufficient positional securing in the circumferentialdirection.

In all three alternative embodiments of the supporting body, a softmaterial with cushioning properties is advantageously used for theremaining regions of the supporting element SEn in each case.

The cover layer SS, designed, for example, in the form of a film, isexpediently applied externally onto the supporting elements SE1 to SEn.If appropriate, the cover layer SS may be designed as atransverse-pressure-resistant tube. The layer SS desirably lies on thesupporting elements SE1 to SEn which, if appropriate, project over theribbon stacks BS1 to BSn, so that they cover the sensitive ribbon stacksBS1 to BSn outwardly. The supporting elements SE1-SEn or theirsupporting bodies STn are expediently curved or rounded in thecircumferential direction in their radially outer regions to ensure aflat bearing-on of the cover layer SS. Between the covering SS and theribbon stacks BS1 to BSn, a free compression space SR is then availableas safety zone. The protective layer SS may advantageously have a hard,thin outer layer HAS and a soft inner layer WIS. The hard outer layerHAS advantageously protects the ribbon stack against deformations. Thesoft inner layer WIS represents a cushion for the ribbon stacks BS1 toBSn.

Finally, a reinforcement BW and/or a multilayer outer sleeve AH may, ifappropriate, be applied to this cover layer SS for protection againstmechanical stresses, so that the optical cable OC1 is produced.

With this cable design, the positional securing of the ribbon stacks BS1to BSn is essentially associated with the supporting elements SE1 toSEn. The latter serve as compression-resistant supporting elements orradial spacers and/or as buffer elements or positional securing betweenthe ribbon stacks BS1 to BSn. By contrast, the ribbon stacks BS1 to BSncan scarcely be mechanically stressed. They form independent, separatelymanufacturable, preferably chamberless lay-up elements which arecomposed of ribbon lines BD1 to BDk loosely laminated one above theother.

As a modification of FIG. 1, in FIG. 2 the core element of the opticalcable OC2 is designed as a tube KR. The elements transferred unchangedare provided with the same reference characters as in FIG. 1. Thetubular outer sheath AM of an optical transmission element contains aplurality of optical waveguides LWL1 to LWLn embedded in a fillingmaterial FM. The strength of the design of the cable core is achieved byan adequate dimensioning of this outer sheath AM. The outer sheath AM isadvantageously built up of a plurality of layers.

Instead of the optical waveguides LWL1 to LWLn, conventional electricalconductors or tensile-load-resistant elements, such as steel or aramidwires for example, may also be introduced, if appropriate, into the coreelement designed as a tube KR. As an alternative to this, however, it isalso possible to leave this tube KR empty and use it, for example, forthe longitudinal ducting of pressurized gas for the purpose ofmonitoring the optical cable OC2.

FIG. 3 shows an optical cable OC3 constructed in two layers. Its cablecore has an identical, by analogy with FIG. 1, inner layer LA1 with acover layer SS1. Elements transferred unchanged from FIG. 1 are providedwith the same reference characters as in FIG. 1. On this first, innerlayer LA1 there is applied a similarly constructed, second lay-up layerLA2 with supporting elements SE1* to SEn*, with ribbon stacks BS1* toBSn* and with a cover layer SS2* arranged thereon. In the outer layerLA2, ribbon stacks and/or supporting bodies different in shape and sizefrom the inner layer LA1 may expediently be used.

Multilayer arrangements are expediently laid up in reversed-lay. By thismeans, a secured, continuous supporting of the supporting elements ofthe various layers is ensured.

FIG. 4 illustrates how an optical cable OC1 according to FIG. 1 can beproduced. The central core element KE is taken off, corresponding to thearrow TR to the right-hand side, from a rotating supply bobbin VKE. Fromsupply bobbins (VBD11 to VBD1k, . . . , VBDn1 to VBDnk), which arearranged in a fixed annular manner around the longitudinal axis of thecore element KE, optical waveguide ribbons BD1 to BDk are unwound. Theseare assembled to form approximately rectangular ribbon stacks BS1 to BSn(indicated by small rectangles in FIG. 4) and are fed to a common lay-uppoint VP in a device VVN (which is designed analogously to a lay-upnipple). At the lay-up point of the device VVn, the rectangular ribbonstacks BS1 to BSn are laid up annularly around the core element KE.Simultaneously with this lay-up operation of the ribbon stacks BS1 toBSn, the supporting elements SE1 to SEn are unwound in a downstreamsecond rotationally symmetrical and fixed arrangement of supply bobbinsVSE1 to VSEn and also fed to the common lay-up point VP of the deviceVVN. The supporting elements SE1 to SEn are introduced from the outsidebetween the interstices of the ribbon stacks BS1 to BSn. For theprotection of the ribbon stacks BS1 to BSn against deformations andcompressions, a cover layer SS is extruded with the aid of a downstreamextruder EX1 onto this layer of supporting elements SE1 to SEn. For theadditional mechanical protection against tensile, flexural and torsionalstresses, a reinforcement BW may advantageously be applied to the coverlayer SS with a device BWV. In the extruder EX2, a multilayer outersleeve AH is finally applied onto the reinforcement BW if appropriate. Adownstream, rotating caterpillar take-off unit RA positively grasps theoptical cable OC1 thus produced and feeds it to a rotating winding drumTL. In this arrangement, the caterpillar take-off unit RA serves thepurpose of taking off the central core element KE from its supply bobbinVKE, taking off the lay-up elements such as the optical waveguide ribbonlines BD1 to BDk and the supporting elements SE1 to SEn from theirsupply bobbins and feeding them to their common lay-up point in thedevice VVN. Torsion of the central core element KE is prevented in thatthe drums VKE and TL and the caterpillar take-off unit RA rotatesynchronously and codirectionally.

FIG. 5 shows an apparatus similar to that in FIG. 4 for producing theoptical cable OC1 according to FIG. 1 with the only difference that thesupply bobbins VSE1 to VSEn for the supporting elements SE1-SEn areomitted. The elements transferred unchanged are provided with the samereference characters as in FIG. 4. An extruder EXS with an extruder headEK designed as a multi-orifice die is arranged downstream of the deviceVVN. In this arrangement, the die orifices of the multi-orifice die inthe extruder head EK correspond to the profile of the supportingelements SE1 to SEn. During the production process, independent profilesof supporting elements SE1 to SEn are extruded from the multi-orificedie of the extruder head EK. These are cooled and brought by means ofthe feed device ESE to their intended position between the ribbon stacksBS1-BSn.

If appropriate, the ribbon stacks BS1-BSn with the supporting elementsSE1-SEn to be introduced between them can also be SZ laid up. In thiscase the two supply bobbins VKE and TL, for example, are fixed, whereasthe central element KE and the cable core are rotated or twisted, withalternating lay direction, on a lay-up route between a first additionalcaterpillar take-off unit, corresponding to RA, upsteam of the lay-pointVP and the caterpillar take-off unit RA. These two SZ caterpillartake-off units advantageously rotate approximately synchronously. Theadditional caterpillar take-off unit has been omitted in FIG. 5 for thepurpose of clarity.

We claim:
 1. An optical cable comprising: a core element, a plurality ofribbon stacks, each stack being formed by a plurality of opticalwaveguide ribbons, said stacks being arranged in at least one layeraround said core element and supporting elements adjacent to the ribbonstacks said supporting elements being designed as independent profilesand each of said supporting elements being arranged in the interspacebetween two adjacent ribbon stacks, said supporting elements extendingin radial direction at least as far as the ribbon stacks and lying withtheir inner ends on the core element such that said supporting elementscontribute for positionally securing the ribbon stacks relative to eachother.
 2. The optical cable of claim 1 wherein the core element furthercomprises at least one tensile-load-resistant element.
 3. The opticalcable of claim 2 wherein a thickening layer is applied to thetensile-load-resistant element.
 4. The optical cable of claim 1 whereinthe core element is a tube.
 5. The optical cable of claim 4 wherein atleast one optical waveguide is located in the tube.
 6. The optical cableof claim 1 wherein the plurality of ribbon stacks are curved in anarcuate manner around the core element.
 7. The optical cable of claim 1wherein the optical waveguide ribbons form approximately rectangularribbon stacks.
 8. The optical cable of claim 1 wherein the opticalwaveguide ribbons within a their ribbon stack are provided with anincreasing number of optical waveguides towards the outside.
 9. Theoptical cable of claim 1 wherein a radial extent of a ribbon stack issmaller than its extent about the circumference.
 10. The optical cableof claim 9 wherein the radial extend is between 1 mm and 3 mm, and theextend along the circumference is between 1.5 mm and 5 mm.
 11. Theoptical cable of claim 1 wherein each of the ribbon stacks has between 2and 10 optical waveguide ribbons and each of the waveguide ribbons hasfrom 2 to 16 optical waveguides.
 12. The optical cable of claim 1further comprising:a filling material between the optical waveguideribbons.
 13. The optical cable of claim 12 wherein the filling materialis adhesive.
 14. The optical cable of claim 1 wherein the ribbon stacksare laid up on the core element.
 15. The optical cable of claim 14wherein a lay length of the ribbon stacks is between 400 mm and 700 mm.16. The optical cable of claim 1 wherein adjacent ribbon stacks have aclearance at their base between 0.5 mm and 1.5 mm.
 17. The optical cableof claim 1 wherein the supporting elements only partly fill intersticesbetween the ribbon stacks.
 18. The optical cable of claim 1 wherein thesupporting elements completely fill the interstices between the ribbonstacks.
 19. The optical cable of claim 1 wherein the supporting elementshave an approximately wedge-shaped cross section.
 20. The optical cableof claim 1 wherein the supporting elements comprise a stiff material.21. The optical cable of claim 1 wherein the supporting elementscomprise an easily deformable material.
 22. The optical cable of claim 1wherein the supporting elements comprise a material containing aswelling agent.
 23. The optical cable of claim 1 wherein the supportingelements are comprised of a material having a modulus of elasticitybetween 0.001 and 1N/mm².
 24. The optical cable of claim 1 wherein thesupporting elements are further comprised of a radially extending hardsupporting body in the interior and a cushioning outer region.
 25. Theoptical cable of claim 1 wherein a stiff supporting body runstransversely to a radial extent of the supporting elements.
 26. Theoptical cable of claim 1 wherein the supporting element is furthercomprised of a T-girder-shaped supporting body.
 27. The optical cable ofclaim 1 wherein the supporting elements are in a fixed position.
 28. Theoptical cable of claim 1 further comprising:a cover layer applied ontothe ribbon stacks and the supporting elements.
 29. The optical cable ofclaim 28 wherein the cover layer comprises a thin, hard outer layer. 30.The optical cable of claim 28 wherein the cover layer comprises acushioning inner layer.
 31. The optical cable of claim 28 furthercomprising:an outer sheath applied to the cover layer.
 32. The opticalcable of claim 1 wherein the ribbon stacks are located in chamberelements.
 33. A method for producing an optical cable comprising thesteps of:supplying a plurality if ribbon stacks, each of said stacksbeing formed by at least one layer of optical waveguide ribbons;attaching the plurality of ribbon stacks to a core element; andsupplying and securing support elements into interspaces betweenadjacent ribbon stacks on the core element to secure the ribbon stacksin position relative to each other.
 34. The method of claim 33, furthercomprising:the additional step of applying an additional layer of ribbonstacks and support elements.
 35. The method of claim 33 wherein theribbon stacks and supporting elements are laid up jointly in arespective layer.
 36. The method of claim 33 wherein the step ofsupplying a plurality of ribbon stacks comprises the additional step ofremoving optical waveguide ribbons from an optical waveguide supplybobbin, and wherein the step of supplying support elements comprises theadditional step of removing support elements from a support elementbobbin.
 37. The method of claim 33 wherein after the step of attachingthe ribbon stacks the method further comprises:the additional step ofpassing the ribbon stacks through an extruder and extruding profiles forsupport elements.
 38. The process of claim 33 comprising the additionalstep of applying a cover layer on top of the ribbon stacks and supportelements.
 39. The process of claim 33 comprising the additional step ofexternally applying an outer sleeve on top of the ribbon stacks andsupport elements.